package com.example.springbootdoc.utils;

import freemarker.template.Configuration;
import freemarker.template.Template;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.Map;

/**
 * word导出工具
 */
@Slf4j
public class WordUtils {

    private WordUtils() {
    }

    private static Configuration configuration = null;//配置

    private static String templateFolder;

    static {
        templateFolder = Thread.currentThread().getContextClassLoader().getResource("").getPath() + "template";
        configuration = new Configuration();
        configuration.setDefaultEncoding("utf-8");
        try {
            System.out.println("模板配置路径:" + templateFolder);
            configuration.setDirectoryForTemplateLoading(new File(templateFolder));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    /**
     * 导出word
     *
     * @param request
     * @param response
     * @param map      参数
     * @param wordName 模板名，示例xxx.ftl
     * @param fileName 要到处的word文件名称,示例:test.doc
     * @param name     临时文件名
     * @throws IOException
     */
    public static void exportMillCertificateWord(HttpServletRequest request, HttpServletResponse response, Map map, String wordName, String fileName, String name) throws IOException {
        Template freemarkerTemplate = configuration.getTemplate(wordName);
        File file = null;
        InputStream fin = null;
        ServletOutputStream out = null;
        try {
            // 调用createDoc方法生成Word文档
            file = createDoc(map, freemarkerTemplate, name);
            fin = new FileInputStream(file);
            response.setCharacterEncoding("utf-8");
            response.setContentType("application/x-download");
            fileName = new String(fileName.getBytes(), "ISO-8859-1");
            response.setHeader("Content-Disposition", "attachment;filename=".concat(fileName));
            out = response.getOutputStream();
            byte[] buffer = new byte[1024];// 缓冲区
            int bytesToRead = -1;
            // 通过循环将读入的Word文件的内容输出到浏览器中
            while ((bytesToRead = fin.read(buffer)) != -1) {
                out.write(buffer, 0, bytesToRead);
            }
        } finally {
            if (fin != null) {
                fin.close();
            }
            if (out != null) {
                out.close();
            }
            if (file != null) {
                file.delete();// 删除临时文件
            }
        }
    }

    private static File createDoc(Map<?, ?> dataMap, Template template, String name) {
        File f = new File(name);
        Template t = template;
        try {
            //这个地方不能使用FileWriter因为需要指定编码类型否则生成的Word文档会因为有无法识别的编码而无法打开
            Writer w = new OutputStreamWriter(new FileOutputStream(f), "utf-8");
            t.process(dataMap, w);
            w.close();
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }
        return f;
    }
}
